1. Field of the Invention
This invention relates to cleaning compositions and more particularly is directed to such compositions having a thixotropic paste-like nature, which can be advantageously employed to clean non-horizontal surfaces, especially vertical surfaces of textile materials.
2. Prior Art
Cleaners have utilized a number of different chemical and physical actions in performing their function. Dissolving the soil, abrading it from the surface to be cleaned, and floating it away from the soiled surface by application of a surfactant, are all commonly used mechanisms for removing soil from a substrate. Paste-like cleaners are particularly useful for cleaning vertical or other non-horizontal surfaces where liquid material might run down, streak, and even spread the soil to another part of the surface. Thixotropic gel cleaners have been disclosed for cleaning metal surfaces, but these cleaners incorporate acids to dissolve corrosion products on the metal surfaces. Paste type cleaners such as those disclosed in U.S. Pat. No. 2,728,729 are also available for cleaning wall paper and painted walls; however, these cleaners are not thixotropic but are cohesive instead, and resist crumbling in use.
More recently dry powder cleaners have been developed wherein the cleaning mechanism depends to a large extent on the transfer of soil from its lodging on a substrate to the surface of porous particles through the agency of a solvent or solvents and a mechanical agitating action. Such powders are disclosed in copending application Ser. No. 209,402 filed Dec. 17, 1971, now abandoned. Evaporation of the solvent or a substantial part of it leaves dry particles containing the soil which can be removed by suction or by brushing. Powdered cleaning compositions, while useful on horizontal surfaces such as carpets, cannot be used conveniently on vertical surfaces such as drapes, stair risers, or carpeted walls because they do not adhere sufficiently, tending to fall off the surface before their solvents can penetrate the stained surface and exert their cleaning function. This invention is directed to a composition by which this cleaning mechanism can be applied to vertical or other non-horizontal surfaces without the disadvantages of prior art cleaning compositions.